O Radio, O Radio, What Art Thou?

That’s right this time around I will look into our friend in solitude our life saver in desperate times, the “Radio”. The radio is like the nitro that speeded up the telecommunication industry and allowed us to get rid of those hideous wires.
The story is some what like this, after the discovery of radio waves in 1888 an Italian genius named Marconi got a bright idea. The idea was to use radio waves to communicate .This made Marconi one of the pioneers in wireless radio communications. Marconi was successful in introducing radiotelegraph to the world. The importance of the radiotelegraph became more evident when operators from Marconi’s company were the ones to signal in for help which saved around 700 lives during the Titanic wreck. The radiotelegraph didn’t look anything like the radio sets of today. The telegraph was far away from commercial purpose radios as it was able to only communicate in Morse code.

But soon enough Morse code was replaced by speech and music with the introduction of the crystal radio sets around the early 1900s. The credits for this invention goes to an array of scientists as they combined their magical ideas to give us the first radio sets that were able to receive music and speech. The crystal radio sets didn’t require any kind of power supply the radio waves were enough to power up these babies.

1922 Crystal Radio

The crystal radios contained crystals of galena or pyrites which acted as detectors much like the diodes of today. The crystal radios did give sound but quality of the sound needed some fixing up. That’s when the thermionicvlave entered the picture. The thermionicvalves were also known as vacuum tubes. The valves emitted electron after being heated up. They allowed inventors to switch amplify or modify electrical signal by controlling the electron flow and replaced solid state diodes.

Though the valve radios gave quality sound they didn’t appease the users because of their heavy and ugly looking bodies. It was around 1930s that companies like Marconi-phone started building radios that complemented the furniture. This fashionable trend took off from that time onwards with radios. New models of radios had press buttons to preset channels and wooden or metallic exteriors were replaced by bakelite exterior. No the radio wasn’t ugly any more but had changed into a work of art.

A Two Valve Radio 1924

However, the biggest break through in the industry came with the advent of transistors. Using transistors instead of valves in radios reduced power consumption and allowed the use of lighter batteries. In electronics, a transistor is a semiconductor device commonly used to amplify or switch electronic signals. A transistor is made of a solid piece of a semiconductor material, with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current flowing through another pair of terminals. Because the controlled (output) power can be much larger than the controlling (input) power, the transistor provides amplification of a signal. The transistor is the fundamental building block of modern electronic devices like the radio. Transistors paved the way for portable radios which hit the market with a bang and the people, well they just fell in love with the cute radio sets.

The first commercially successful transistor radio was the Sony TR-55 (as shown in the picture on the right), introduced in 1955.

The radios after this just kept coming in all different sizes and designs. In 1933 Trevor Baylis was watching a program about AIDS in Africa, and realized that many people in developing countries had no radio (and so had limited access to health information) because they had no mains electricity.

He developed the wind-up radio. Windup radio is a radio that is powered by human muscle power rather than batteries or the electrical grid. In the most common arrangement, an internal electrical generator is run by a mainspring, which is wound by a hand crank on the case. Turning the crank winds the spring, and a full winding will allow several hours of operation. The wind-up radio was succeeded by the digital radio that received signals as digital code ensuring clearer sound Because of the way in which the signal can be compressed, more radio stations can be transmitted using the same range of frequencies (‘bandwidth’).

The digital signal includes information about the channel, making it easier to ‘tune in’ (there is no need to remember the frequency). A display on the radio can show the program, the name of the track currently being played, email addresses, up to the minute sports results or competition details, making it more informative.

The development of IC circuits was like a blessing from GOD as it allowed the development of smaller and cheaper and well designed radios. The ICs of today can hold a number of transistors, resistors capacitors all in a tiny amount of space. Thus people know can enjoy the radio even in the poorest parts of the world. The development of the radio was truly amazing from the huge radiotelegraphs to the modern day handheld digital radios. Thanks to a large number of scientific discoveries and scientists who combined to give us our pal in sunshine or rain the Radio set.
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By By Tahsin Uddin Mullick
North South University, Dhaka, Bangladesh
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The Aftermath Publications, Issue 2
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